66640717688 has 16 divisors (see below), whose sum is σ = 124960719480. Its totient is φ = 33317859168.

The previous prime is 66640717681. The next prime is 66640717697. The reversal of 66640717688 is 88671704666.

It is a super-3 number, since 3×66640717688³ (a number of 33 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66640717681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196631 + ... + 414662.

Almost surely, 2^66640717688 is an apocalyptic number.

It is an amenable number.

66640717688 is a deficient number, since it is larger than the sum of its proper divisors (58320001792).

66640717688 is a wasteful number, since it uses less digits than its factorization.

66640717688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624926 (or 624922 counting only the distinct ones).

The product of its (nonzero) digits is 16257024, while the sum is 59.

The spelling of 66640717688 in words is "sixty-six billion, six hundred forty million, seven hundred seventeen thousand, six hundred eighty-eight".